Two simple rules for the Mass
There have been two true religions in this world. The Jewish religion and the Catholic religion.
In Old Testament times
God established one Church in the Jewish religion, through the mediation of Moses. This religion had a ministerial priesthood and a common priesthood. An altar and a sacrificial system. Succession of authority through the High Priest. And, there was only one true religion.
Until Jesus came
In the New Testament, God established one Holy Catholic Church in the Christian religion, through the mediation of Jesus Christ. This religion also has a ministerial priesthood and a common priesthood. An altar and a sacrificial system. Succession of authority through the Bishopric (i.e. High Priest). And, since this religion fulfilled the Jewish religion, it is now the one True Religion in the world.
1500 years later
Along comes Martin Luther. He established a set of doctrines which result in thousands of competing churches. A common priesthood, but not ministerial priesthood. No altar. No sacrificial system. And there is no true religion amongst them because every denomination has their own belief system with doctrines that contradict one another.
After Martin Luther
Many others have come, changing his religion even further. Splintering and forming more religions.
God doesn’t change
He is the same, yesterday, today and tomorrow. Therefore, His Religion hasn’t changed. The Catholic Church is the archetype of God’s religion. When God made the Jewish religion, He had Moses make it according to the pattern of the archetype. The Jewish religion was a shadow of the Christian religion. The Catholic Church. The one on the Mountain:
Hebrews 12:22 No, you have approached Mount Zion and the city of the living God, the heavenly Jerusalem, and countless angels in festal gathering, 23 and the assembly of the firstborn enrolled in heaven, and God the judge of all, and the spirits of the just made perfect, 24 and Jesus, the mediator of a new covenant, and the sprinkled blood that speaks more eloquently than that of Abel.